Textile process



Sept. 8, 1936. w. WHITEHEAD TEXTILE PROCESS,

Filed Dec. 28, 1932 INVENTOR William Wh'eheod ATTORN EYS smeared sept. s, rese U ETE@ S'ES,

andere l 'rnx'rmn rnoenss William Whitehead, Cumberland, Md., assigner `to Celanese Corporation of America, a corporation of Delaware Application December 28, 1932, Serial No. 649,137 ii Claims. (Cl. ill-fill) This invention relates to the preparation of yarns and iilaments having a coating of waxlike material thereon, and relates more particularly to artificial filaments made of organic. de-

rivatives of cellulose that are coated with wax.

An objectv of my invention is to coat yarns or laments with wax-like material in an economiv cal manner. A further object of my invention is `to apply a wax-like material to yarns or iilaments in such a manner that the resulting coating of Wax is-relatively rough so that there is a suicient amount of frictional resistance between windings of such yarns or filaments. Another object of my invention is to provide expediente `for applying such wax-like material to such yarns or laments while they are in transit.

For certain purposes, it is desirable to apply a coating of wax to yarns. For instance in the case of yarns that are to be wound around metal/lic wire to be used as electric-al conductors,

' a coating of Wax on such yarns is desirable not only to increase the electric insulating properties of such yarns, but(also to increase the frictional resistance between the windings of the yarns on the packages from which they are supplied. In the` case of Wrapping of wire, the yarn is supplied from one or more .packages which are rapidly 'rotated abo t: the wire, and this rapid rotation of the packages together with the severe vibrations set up'in the wrapping machine tend to cause the yarns, if they have smooth surfaces, to unwind from the packages more rapidly than they are consumed in the operation of Wrapping of the wire, with the result thatsnarling takes place. In order to prevent this phenomenon, which is known as sluffing-off, it is necessary that the coating of wax on the yarn be relatively rough so that there is suliicient frictional resistance between the windings of the coated yarn. 4

I have found that if the wax is applied to the yarn from a solution in a good solvent, for instance from a solution of paraiiin wax in kerosene, naphtha or other low boiling solvents, the coating of wax resulting from the evaporation of the solvent is entirely too smooth to prevent this sluiting-oir. I have discovered however that if the wax-like materiall is applied in liquidI condition' under such circumstances that it is liquid atpelevated temperatures but solidies. upon reduction of temperature, the\resulting coating is suiiiciently rough to enable the formation of hard packages from yarns so coated, from which packages the yarns do not sluff ofi when subjected to severe textile operations, such madeA from ozokerite.

lsuch as crystalline paraiiin wax, beeswax, carnauba wax, or other waxy materials such as cetyl -the yarns or iilaments `the yarns or as for example in the wrapping oi electric wires.

In accordance with my invention, I apply to yarns or filaments a coating of wax-like material under such circumstances that the wax-like material is in liquid condition because of ele- 5 vated temperatures but solidifies after its application to the yarns or filaments upon reduction of temperature, whereby there is deposited upon the same a coatinghthat is not smooth or slippery.

This invention is applicablev to the treatment l0 of yarns or filaments, under which terms are included, threads, assemblies or bundles of a number of continuous iilaments which may be in parallel relationship or which may be twisted together, articial bristles, straws, short lengths 15 of staple fibres, or yarn spun -from such staple fibres. v

This invention is particularly of importance in connection with the treatment of yarns or filaments made of cellulose acetate or other organic 20 derivatives of cellulose such as cellulose formate,l cellulose propionate, cellulose butyrate or other organic esters of cellulose or methyl cellulose, ethyl cellulose or benzyl cellulose orother cellulose ethers'. However it is also applicable to 25 the treatment of yarns or filaments made of other bres such as natural silk, reconstituted cellulose.' cotton, linen, etc.

As the Wax-like material, I prefer to employ an amorphous parafn wax, which may be produced 3o from petroleum or which may be ceresin Wax However, other waxes alcohol or the esters or ethers of higher fatty ,35 alcohols may be employed. A mixture of two or more of such wax-like materials may likewise be employed.

If it be desired to reduce the combustibility or inammability of the product, fire retardants, 40.

such as beta chlornaphthalene (halowax), trlphenyl phosphate or tricresyl phosphate, may be incorporated either in the wax-like material or in or both. t th wax-like material is applied to ll5 lilaments while in a Vmolten conditionl and preferably at a temperature just sulilc'ient to keep it molten or at most only a few degrees, say l to 15 F., above the melting point, so that upon a slight cooling, the wax-,like mate- 50 rial solidies upon the yarns orl'laments.' If the wax is applied at temperatures considerably above the melting point, it tends to form a relatively smooth film on the yarn. s.

The application of the wax-like material to Preferably the yarn while it is in transit from the spin- ,ning machine in which it is formed or from a package on to a package into which it is wound is preferable, since it presents many distinct advantages over the application of wax to yarn while in the form of hanks. The treatment of yarn in hanks or skeins is expensive because of the many winding operations required and the frequent damage to the yarn when so handled. Moreover when hanks are dipped in a solution of-wax, variations in Vwang content result due to uneven accumulation of the wax solution on the hanks because of the draining of the` solution from the hanks as they are suspended for drying. This irregularity of deposition of wax on the yarn causes an objectionable variation in the covering power of the yarn and in its spacing when wrapped around wires or used for other purposes.

The wax-like material may be applied to the travelling yarn by any suitable devices such as i wicks, discs or smooth, grooved or serrated rollers, the lower portions of which are immersed in the liquid wax-like material. The yarns or filaments may then be wound with or without twist on to any suitable packages, such as cheeses, bobbins, bottle bobbins or other desired packages. The yarn may be Wound at any practical feed rate, say from 10 to 300l metres per minute. The amount of Wax applied may be any suitable or desired quantity, say fromA l to 20% of the weight of the yarn, preferably 3 to '7%.`

If it is desired to apply the wax at a temperature somewhat above the melting point, so that it does not solidify unaided by the time the yarn reaches the winding device, the cooling and solidification of the wax may be aided by contacting the yarn, immediately after the wax has been applied, with a cold metal surface, a wick supplying cold water or other cool liquid, orvfa blast of cold air or other gas.

In order further to improve the physical prop- `erties of the coating of wax-like material, there may be applied to the yarns or filaments after the application of the molten fwax, a substance such as amyl acetate or butyl acetate, which is a solvent for the wax while warm. but which precipitates the `wax out of solution sharply on cooling.

An important aspect of this invention is the 4to electrochemical effects, detract from the electrical insulating properties of such yarn. However I have found that such lubrication may be dispensed with if the wax-like material is applied to the artificial filaments a`s they leave' the spinning cabinet. Moreover, since the bundle of filaments formed during spinning is preferably employed in the untwisted or parallel form, the

I multiple ends of untwisted filaments leaving 'he spinning chamber, after the application of waxlike material, may be wound directly without twist on to cheeses or other convenient packages.

C heeses or packages made-in accordance with .'this invention contain yarns or' filaments on which 'the wax is uniformly applied in such a physicaly condition as to impart to the yarns such surfaces as toJprevent the package from collapsing or slufling-oif in transit or on machines employed for Wrapping the yarn wound wires.

This invention is of great importance for the preparation of yarns or filaments to be employed as insulating material in electrical devices, such as for the wrapping of copper or other metallic wires or conductors to be used for many purposes, such as telephone or telegraph wires,

solenoids, armatures, relays, etc. However this invention may be used for the treatment of yarns or filaments for other purposes. For instance the wax may be applied alone, or in association With soaps or other saponifying agents to facilitate the subsequent removal of the wax, to yarns which may be subsequently employed for making Woven or knitted fabrics or for other textile opl erations such as plural and ply winding to assist the yarn in forming( solid packages that do not slurf-off in severe textile processes. Likewise the wax-like material may beapplied as a size to yarns to be used as warps in fabric-forming operations. Staple fibres, such as relatively short lengths of cellulose acetate filaments, may have the wax-like material applied thereto before, during or after anysuitable operation involving the formation of spun yarn; for instance in the operation of drafting or drawing sliver containing such spun yarn, the `lower portions of one or more of the drafting rolls may rotate in a bath Fig..2 shows another form of device for applying the wax and also a liquid to the laments or yarns.

Referring to Fig. 1 the filaments I are extruded from a solution of` cellulose acetate or other organic derivative of cellulose in a volatile solvent through oriiices of the; spinning jet 2 Within a dry spinning chamber 3, through which heated air or other evaporative medium passes. 'I'he filaments I pass out of the slot 4 of 'the chamber 3, and are drawn to the winding device 5 to form a suitable package, which is yshown on the drawing as a cheese.

In transit, the yarns or filaments I are caused t0 contact with the rotating roller 6 rotating on an axis substantially at right angles to the path of the yarns and driven through belt 'I by pulley 8. The lower portion of the roller 6 is immersed in the bath lof wax 9 in tank I 0, the wax being maintained in molten state by the closed steam coil II.

Referring to Fig. 2, the yarns or filaments I may be drawn from a spinning chamber in which they are formed or from a Vvsuitable ,package such as bobbin, hank, cone orcheese, and are caused to pass over the edge ofa discv I2 which is rotating around an axis substantially parallel to the path of the yarns I. The disc I2 is caused to rotate by means of the belt I3 and pulley I 4 and is so mounted that its lower portion is submerged in the bath of Wax 9 which is heated by means of the closed steam coil II.

After contacting with the disc I2, and prior to being wound on the cheese 5, .the yarns I are caused to contact with the wick I5 which furnishes thereto a liquid contained in the trough I 6.

fcold amyl acetate,

wax, or it may be a liquid, such as amyl acetate,

.which is a solvent for wax at elevated tempera.-

' Example I Referring to Fig. 1, an' amorphous paraiiin wax having a melting point of 168 F. is placed in trough I and is heated to 170 F. by the coil II. The roller 6, which may be a diameter of 2", is caused to rotate at about 15 revolutions per minute. The bundle of filaments I, which are formed in the spinning chamber 3 by the extrusion of a solution of cellulose acetate in acetone through the jets 2, and which may have a denier of 100 to 200, are caused to contact with the roller 6 while being wound at the rate of 200 meters vper minute'onto the cheese 5 without twist. In this manner an amount of wax, equal to 5% of the weight of the filaments, is applied.

No other finish need be applied to lthe yarns or filaments, the wax being sufficiently lubricative for all textile processing involved.

Instead of drawing the filaments from a spinning chamber, the filaments or yarns may be drawn from a bobbin, hank, cheese, or other suitable package to have thewax applied thereto.

Example II The process of Example I is followed except that instead of using pure amorphous paraffin Referring to Fig. 2, amorphous parafiin wax having a melting point of 168 trough 9 and heated by coil .II to 170 F. -The yarns or filaments I, either directly from a spinning chamber or from a textile package, is caused to pass across the edge of the rotating disc I2 dipping in the bath 9 of the wax. Immediately after the yarn leaves the disc I2, it is caused to contact with the wick I which applies an amount of amyl acetate equal to 5% of the weight of the yarn. The amyl acetate dissolves at least some of the warmwax, but since the wax is only slightly soluble in the hot amyl acetate and not soluble in the wax precipitates sharply from the solution in amyl acetate on cooling. As a consequence, the desirable rough surface of the Wax is further roughened `and its frictional resistance is further enhanced.

F. is placed in' It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of my invention.

Having described my invention, what I` desire to secure by Letters Patent is:

1. Method of dressing yarns or filaments of organic derivatives of cellulose, which comprises forming a rough coating of wax thereon by applying molten wax thereto at a temperature not substantially exceeding F. above the melting point of the wax, and thereafter cooling below me melting point of the wax.

2. Method of dressing yarns or filaments of cellulose acetate, which comprises forming a rough coating of wax thereon by applying molten amorphous paraflin wax thereto at a temperature not substantially exceeding 15 F. above the melting point of the wax, and thereafter cooling below the melting point of the wax.

3. Method of dressing yarns or filaments, which comprises forming a rough coating of wax thereon by applying molten wax thereto at a temperature not substantially exceeding the melting point of the wax; then applying thereto, while the wax is still warm, a liquid which is a solvent for the wax at elevated temperatures but which is a non-solvent at lower after cooling belowthe melting point of the wax.

4. Method of dressing yarns or filaments of cellulose acetate, which comprises forming a rough coating of wax thereon by applying molten wax thereto at a temperature not substantially exceeding the melting point of the wax, then applying thereto, while the wax is still warm, a liquid which is a solvent for thewax at elevated temperatures but winch is a. non-solvent at lower temperatures, and thereafter cooling below the melting point of the Wax.

5. Method of dressing yarns or filaments of cellulose acetate, which comprises forming a rough coating of wax thereon by applying molten wax thereto at a temperature not substantially exceeding the melting point of the wax, then applying amyl acetate to the wax while the wax is still warm, and thereafter cooling below the melting point of the wax.

6. Method of dressing yarns or filaments of cellulose acetate, which comprises forming a rough coating of wax thereon by applying molten wax thereto at a temperature not substantially temperatures, and thereexceeding the melting point of the Wax, then ap- WILLIAM WHI'IEr-IEAD.v 

